To save the drowning child, the boy plunged into the icy water without hesitation, ________ his own

To save the drowning child, the boy plunged into the icy water without hesitation, ________ his own safety．

A.despite of

B.regardless of

C.unaware of

D.because of

答案及解析： B

解析：

本题考查介词词组的用法及区别。regardless of意思是“不管，不顾”；

despite of“尽管”，表示让步；

unaware of意思是“没有觉察到”；

because of意思是“因为”，表示原因。