请教，这题为什么不能理解成目的状语

Among the objects found in the excavated temple were small terra-cotta effigies left by supplicants who were either asking the goddess Bona Dea's aid in healing physical and mental ills or thanking her for such help.

a.in healing physical and mental ills or thanking her for such help

b.in healing physical and mental ills and to thank her for helping

c.in healing physical and mental ills, and thanking her for helping

d.to heal physical and mental ills or to thank her for such help

e.to heal physical and mental ills or thanking her for such help请教，这题为什么不能理解成目的状语

aid in v+ing is idiom.so couldn't change

哦，谢谢啊