Can I change the cantrip I get from my Pact Boon with Eldritch Versatility?

Question

I need to check with my GM first whether this is allowed but I'm considering retraining one of my fourth level Warlock's cantrips she learnt from her Pact of the Tome. Looking at the optional class feature Eldritch Versatility (introduced in Tasha's Cauldron of Everything, p. 70), one of the bullet points says:

Replace the option you chose for the Pact Boon feature with one of that feature’s other options.

Does this mean a) Change my Pact Boon entirely (in my case from Pact of the Tome to something else) or b) Replace the options picked as part of that Pact Book (in my case a cantrip learnt from Pact of the Tome with another from any class's spell list). I suppose if I could pick the same Pact again a) would lead to b).

Looking at the Pact of the Tome feature, it says in part:

Your patron gives you a grimoire called a Book of Shadows. When you gain this feature, choose three cantrips from any class’s spell list (the three needn’t be from the same list). While the book is on your person, you can cast those cantrips at will. They don’t count against your number of cantrips known. If they don’t appear on the warlock spell list, they are nonetheless warlock spells for you.

Emphasis mine.

Another of the bullet points under Eldritch Versatility says this:

Replace one cantrip you learned from this class’s Pact Magic feature with another cantrip from the warlock spell list.

If I wanted to re-pick one of the cantrips from the Pact Boon (not Pact Magic) it could be from any class's spell list. The above bullet point alone wouldn't permit that.

Can my warlock use Eldritch Versatility to change the cantrip I get from Pact of the Tome?

Answer 1

Eldritch versatility allows you to change your Pact Boon to a different Pact Boon.

The question here is about what "option" means when the feature says:

Replace the option you chose for the Pact Boon feature with one of that feature’s other options.

The optional class feature that comes immediately before Eldritch Versatility actually tells what "option" means with respect to the Pact Boon feature:

Pact Boon Option

3rd-level warlock feature

When you choose your Pact Boon feature, the following option is available to you.

Pact of the Talisman

Ergo, Eldritch Versatility is allowing you to replace your Pact Boon, meaning Pact of the Blade, Chain, Tome, or Talisman, with a different one of those four options. The cantrips you select as part of Pact of the Tome are not what the feature is referring to.

To look at it another way, Eldritch Versatility directs you to the "Pact Boon" feature specifically, not the particular pact boon you selected, when it says:

Replace the option you chose for the Pact Boon feature

Reading this, go first to the feature that is literally named Pact Boon, which reads:

Pact Boon

At 3rd level, your otherworldly patron bestows a gift upon you for your loyal service. You gain one of the following features of your choice.

From here, it should be clear what "options" Eldritch Versatility is referring to - those features you may choose when you first get the Pact Boon feature, Pact of the Blade, Chain, Tome, or Talisman.