Option 1 (It describes the days being discussed) is correct since it refers to a particular set of days, those in which the subject of the sentence goes jogging, and a particular moment of the day which is the morning.
Option 3 (It creates a compound-complex sentence) is correct because the sentence contains two independent clauses and a dependent clause.
The two independent clauses are: "My mind seems to process ideas faster" and "My mood is more positive". These two independent clauses are joined by the coordinating conjunction "and". The compound-complex sentence also includes a dependent clause "On days when I go jogging in the morning" which is dependent on the two main independent clauses previously mentioned.