Some people called to complain___the net bars that were harming their children's studiesA.at B.for C.with D.about

Some people called to complain___the net bars that were harming their children's studiesA.at B.for C.with D.about
Some people called to complain___the net bars that were harming their children's studies
A.at B.for C.with D.about

Some people called to complain___the net bars that were harming their children's studiesA.at B.for C.with D.about
d about
complain to somebody about something
如果是at后面应该是at the harm of the net bars

D 固定搭配 complain about sth.

D
complain about/of (sth./that...)固定搭配。