The first answer is correct.
"Stop" is one of the verbs that changes a sentence's meaning when followed by a gerund as opposed to being followed by an infinitive. Examples:
Sally stopped going to the gym. (She doesn't go to the gym anymore.)
Sally stopped to go to the gym. (She stopped driving the car or doing another activity in order to go to the gym.)
"enjoy" can only be followed by a gerund.
There is an entire lists of verbs (and parts of speech) that can:
1. only be followed by a gerund
2. only be followed by an infinitive
3. be followed by either a gerund or an infinitive without a change in meaning
4. be followed by either a gerund or an infinitive but the meaning changes (as with the verb, "stop)
You can find these lists online along with exercises to practice using them.