When Mary Lynn went to the grocery store last week, she took with her several coupons she had received in the mail that week. While at the store, Mary Lynn was offered samples of several food items and she actually bought a few of those, using the in-store coupons. She also bought a particular brand of toothpaste, because the tube came with a free toothbrush. Mary Lynn is taking advantage of:

a) sales promotion.

b) advertising.

c) publicity.

d) viral marketing.

Sales promotion

Explanation:

Sales promotion refers to the process of persuading the client to buy certain product. This is done using different marketing tactics. Advertising refers, as it can be deducted, to the act of making advertising for certain products. Publicity refers to draw attention to certain products through the use of the media. Viral marketing is a technique that induces users to pass on information about a product through social media creating a viral reaction.

In the question, Mary Lynn took coupons she had received, she received free samples of food items that she ended up buying and she bought a toothpaste because it came with a free toothbrush. We can see that Mary Lynn is taking advantage of Sales promotion, since she is being persuaded to buy certain products using different tactics (free products, discounts, tasting, etc)