The Justice Department Has Been Asked to Review a Merger $\text { If Firm A acquires Firm D, what is the HHI for the new market? }$

The Justice Department has been asked to review a merger request for a market with the following four firms.

$\text { If Firm A acquires Firm D, what is the HHI for the new market? }$

A) 100
B) 625
C) 3,906.25
D) 4,687.50