>> Accept her suggestion
I know i'm outnumbered already, but I feel like we've painted Yuruki as a bit of a troublemaker prior. So continuing this trend sounds appealing to me.
>>Ignore the girl and keep walking towards the classroom with Tenshi.
No need to start anything when they're already nearly late for class. That aside, the other options seem like they're bait for conflict to arise.
>> Block the path by spreading his arms wide.
In most situations i'd go with the last of the options, but when it comes to this character I feel his natural reaction would be this. Possibly even leading to the character spouting on about whatever delusion crosses his mind.