I am always delighted when I receive an e­mail from you.the party on July 1st，I shall

I am always delighted when I receive an e­mail from you. the party on July 1st，I shall be pleased to attend. (2013·江苏，26)
A. On account of
B. In response to
C. In view of
D. With regard to

A. On account ofB. In response toC. In view of(答案→)D. With regard to解析：考查介词短语辨析。句意为：当我收到你的e­mail时，我总是很高兴。至于7月1日的聚会，我将很乐意参加。on account of由于，因为；in response to响应，回答；in view of鉴于，考虑到；with regard to至于，关于。

就是这个解释