答案选D
A suffer:
1.做不及物动词,不加宾语,译为受苦.
She suffered greatly as a child.她童年深受苦难.
2.做及物动词,译为忍受.He could not suffer criticism.他不能忍受别人批评他.
B suffer from：
1.患(某种病); 受(某种病痛)折磨You must have suffered from a cold.你一定是感冒了.
2.因…而受罚〔苦,损〕Sometimes I still suffer from these weaknesses.有时我还是在吃这些弱点的苦头.
根据题意,遭受头痛的痛苦,所以应该是suffer from 排除BC,而后面用的是made 过去式,所以前面也应该是过去式.所以选D,再分析suffering,这里可以理解为名词,指代遭受的头痛这种痛苦