The correct answer is "They advise the President on policy matters". Independent executive agencies are technically part of the executive branch, but the are not directly controlled by the President of the United States and they do not advise the President. The Executive Office of the President (EOP) are the agencies that advise the President in policy matters.
Image shows black people voting, so the amendment to the US constitution that directly guarantees the right shown in that image is 15th. 15th amendment of the united states constitution granted the right for citizens to not be denied their right to vote by states or federal government based on their race or color.