In which sentence is the subject-verb agreement correct?

For anyone who wishes to do the work, writing are a satisfying and rewarding career.

Both Ryan and Brady are planning careers in journalism.

Documentary writing, speech writing, textbook writing, and book review writing is just a few of the possibilities.

Both Ryan and Brady are planning careers in journalism.

Explanation:

Both ... and: With this correlative conjunction you need to use a plural verb.

Wrong options:

For anyone who wishes to do the work, writing are a satisfying and rewarding career. (should be is, not are)

Documentary writing, speech writing, textbook writing, and book review writing is just a few of the possibilities. (should be are, not is)