The correct option is A To work
Option A is the correct answer because the sentence has the verb 'agree' that requires an object. The infinitive 'to work' serves as an object to this verb. Also, the sentence seeks to talk about an activity that is happening and will also happen in future. Hence, the use of infinitive ‘to work’ is more appropriate here. Using the gerund ‘working’ in this sentence will not bring out the sense of the activity stretching into the future effectively. Hence, Option C cannot be used here. Options B and D cannot be used as they would render the sentence grammatically incorrect.