The noun 'fleet' refers to a group of: MCQ with Answer and Explanation

Explanation:
'Childhood' is a state, abstract.

Explanation:
As a mass, uncountable. Individual strands: countable (hairs).

Explanation:
'Politics' as a subject or concept is singular: 'Politics is a dirty game.' However, when referring to personal beliefs, it can be plural: 'His politics are leftist.' So both are possible, but typically singular. I'll put A, but mention in solution.