Answer: D. All of the above are required.
Explanation: A celebrity is a famous person who is well-known for their social status which they employ in promoting products, services or in raising awareness concerning certain issues. This is known as celebrity endorsement which attaches the fame of celebrities to brands and products.
For a product to be endorsed by celebrities the claims about the product to be advertised must be verified; most times the products are also made available to them for their personal use to elicit more authentic personal reviews; and sources of claims concerning the product not personally known by the celebrity ought to be disclosed (especially in cases where the celebrity doesn't or can't personally uses the product).
Celebrities inspire consumer confidence, can reach a wider audience and even effectively raising funds geared towards solving problems.