Question

which combining form is spelled incorrectly? a gastr/o b carcen/o c immun/o d nephr/o

Explanation:

The correct combining form for cancer - related terms is "carcin/o", not "carcen/o". "gastr/o" relates to the stomach, "immun/o" to the immune system, and "nephr/o" to the kidney, all of which are correctly spelled combining forms.

Answer:

B. carcen/o