Select the most appropriate option to fill in the blank.

Yesterday, after a nice walk, we ______ to sit on the bench, watch the birds, and rest for a while.

decided

The most appropriate option to fill in the blank is decided.

The sentence is in the past tense, and the verb "decide" needs a past tense form. The past tense form of "decide" is "decided."

The other options are not as appropriate.

• Decide is the infinitive form of the verb "decide." This does not make sense in the context of the sentence, because the action of deciding has already happened.
• Decides is the third person singular present tense form of the verb "decide." This does not make sense in the context of the sentence, because the action of deciding is not happening now.
• Deciding is the present participle form of the verb "decide." This does not make sense in the context of the sentence, because the action of deciding is not happening now.