How can indirect lobbying activities be influential?
a. they are needed to provide candidates to run in elections.
b. emails and phone calls are more effective ways to persuade elected officials.
c. interest groups spend most of their money and time on them.
d. they gain support that increases membership and funds.

Indirect lobbying activities can be influential as they help gain support that increases membership and funds.

Explanation:

Lobbying activities are mostly carried out to get a decision turned in one's favor. To get this done, the lobby groups offer the party in power with funds and more members. Moreover, when a lobby group lobbies against a particular political party, the opposition party gets benefited from it even if it is not associated with the lobby group.