The answer to your question would be that the sentence is written in indicative mood is the following one: Sunset is my favorite time to walk on the beach. That is, your answer would be D.
Mood is the form a verb takes to indicate how it is to be regarded. The indicative mood is a verb form which makes a statement or asks questions. The majority of sentences are in the indicative mood. In addition to this, the main verb in a declarative statement or in an interrogative sentence will be in the indicative more.
