Fielding viewer questions from the floor of the New York Stock Exchange on Wednesday, TheStreet's Jim Cramer had some advice for investors who wanted to know if they should buy Yahoo! (YHOO) stock. 

"We just need to see Rick Hill added to the board," Cramer told TheStreet's Rhonda Schaffler. "If Rick gets on then you've got to buy the stock. Period. That's what you've got to see."

Hill is among a slate of potential directors that activist investor Starboard Value wants to see replace the entire current board of Yahoo!

According to Starboard's March 24 letter to Yahoo! management, "Hill is a seasoned senior executive and public company board member who has served as chairman of Tessera Technologies (TSRA) , a technology company that specializes in inventing, productizing and acquiring intellectual property, since 2013, and who previously served as Tessera's interim CEO.

"Prior to Tessera, Hill spent 20 years at Novellus Systems, a semiconductor equipment designer and manufacturer, where he grew revenues from approximately $60 million to approximately $1.7 billion as CEO and eventually sold the company to Lam Research (LRCX) - Get Report for more than $3 billion."

Cramer believes Hill has created shareholder value throughout his career.

Cramer, who manages the Action Alerts PLUS charitable trust portfolio, also said he's a big fan of Dow Chemical (DOW) - Get Report , an Action Alerts PLUS holding. Dow Chemical is poised to benefit from its planned merger with DuPont (DD) - Get Report .

"Just look at what Ed Breen (CEO of DuPont) did with Tyco (TYC) . You're going to see what he's going to do with Dow and DuPont," said Cramer.

A viewer wanted to know what is needed in order for the biotech sector to get out of its slump. Cramer said a major pharmaceutical company will have to buy a biotech firm.

This article is commentary by an independent contributor. Action Alerts PLUS holds a position in DOW.