Which of the following statements is INVALID?

a. Whether solicited or unsolicited, all research proposals are formal.
b. Informal internal proposals often take the form of an email or a memo.
c. Emphasize key points in your proposal with relevant visuals.
d. Proposals have one primary purpose: to convince your audience to agree to your plan.

Ans: c. Emphasize key points in your proposal with relevant visuals.