John knows he is going to have a hard time convincing people to donate a lot of money to his charity of choice. Therefore, when he approaches people, he often asks for a large donation of $$100.$ More often than not, he gets turned down. After getting turned down, he makes a smaller request and most people comply. What persuasive technique is John using?

$$ Door$-$in$-$the$-$face

Door$-$to$-$door

Dot$-$to$-$dot

Foot$-$in$-$the$-$door