$\rightarrow$ Break down means to separate something into smaller parts.
$\rightarrow$ The subject-word agreement states that
Singular nouns go with singular verbs while plural nouns go with plural verbs.
$\rightarrow$ Expenditure is singular noun and its plural form is expenditures.
The expenditure (singular noun) in the project breaks (singular verb used in the phrase) down as follows
$\rightarrow$ The above statement satisfies the subject verb agreement and hence, the correct option is $C$