Faye Sagler takes a long position in 12 August yttrium futures contracts at a contract price of $ 3.50 per unit. Each contract is for 1000 units of yttrium. The required initial margin is $ 400 per contract and the maintenance margin is $ 300 per contract. August yttrium futures decline to $ 3.42, $ 3.38, and $ 3.31 on the next three trading days. On the first day that Sagler will be required to deposit additional cash into her futures account, the required deposit is closest to:()

A. $ 240.

B. $ 960.

C. $ 1440.

常用基托蜡的软化点为（）

A.26～30℃

B.30～36℃

C.38～40℃

D.40～45℃

E.46～49℃