Which sentence uses a verb that agrees with its subject?
a.
is yolanda at summer camp this week?
b.
was the people playing soccer at the park?
c.
near the coast lives several species of aquatic birds.
d.
in the sky was few clouds.

i think the answer is c

the present continuous is a verb tense which is mainly used to indicates that an action is in progress at the moment of speaking.  

it is formed using: person + verb to be (am/is/are) +verb + - ing form  

example: i am studying at this moment .

in addition, the present continuous is also used in order to express things that will or will not happen in the near future.

example: i am having dinner with some friends tonight.

the speaker sometimes   uses it   to express that an action is repeated and it causes irritation on the part of the speaker

example: my sister is constantly complaining about everything.