They promised out more at home.A. to helpB. helpC. helpingD. helped

问题补充：

They promised out more at home.

A. to help

B. help

C. helping

D. helped

答案：

(答案→)A. to help

B. help

C. helping

D. helped

解析：句意：他们承诺帮助解决更多的家庭困难。动词不定式作宾语表示具体的将要发生的动作，promise后面接不定式作宾语，表示承诺做某事，故选A。