Does the Wild Magic sorcerer's Tides of Chaos feature grant advantage on all attacks, or just the first one?

Question

I have a question regarding the D&D 5e Wild Magic Sorcerer's Tides of Chaos feature, specifically regarding attacking multiple targets with or without advantage.

The Wild Magic sorcerer's Tides of Chaos feature (PHB, p. 103) states:

Starting at 1st level, you can manipulate the forces of chance and chaos to gain advantage on one attack roll, ability check, or saving throw. Once you do so, you must finish a long rest before you can use this feature again.

Any time before you regain the use of this feature, the DM can have you roll on the Wild Magic Surge table immediately after you cast a sorcerer spell of 1st level or higher. You then regain the use of this feature.

Last session, I proclaimed that I would like to cast Scorching Ray (I'm only Level 3) with Tides of Chaos for an advantage boost for my attack roll(s?).

Before my GM could react, I stated that only the first roll (1/3) would be affected by the effect from Tides of Chaos. (In an attempt to increase the speed of combat and with full knowledge about my inability and my GM's that we both do not know the answer to that question.)

Now, this was answered by me before my DM could react. Nobody questions the outcome and all was good. Great.

Now though, a full 48 hours later, I'm questioning my response:
Does Tides of Chaos grant advantage to all attack rolls, even if those attack rolls (may) target multiple targets? Or only the first roll?

Answer 1

No, it does not allow Advantage on all attack rolls

This is spelled out quite explicitly in the rules you quoted:

Starting at 1st level, you can manipulate the forces of chance and chaos to gain advantage on one attack roll, ability check, or saving throw.

So you did right the first time.