1.) He should’ve said nothing as he wasn’t willing to do the conversion therapy and therefore quite possibly let the kid go to a real conversion therapy “camp” of which usually inflict lasting harm.
2.) Actually have done the conversion therapy as asked.
3.) Lie as described in the OP
You said “good for the kid” indicating that you think that conversion therapy is a bad thing but also somehow came to the conclusion that 3. is the least moral choice? What? Baffling.