The correct answer is D (All of the above).
Environment contains many carcinogenic chemicals, which a person can inhale, resulting in cancer. Chronic inflammation can cause DNA change, which may further result in cancer/enhancement of cancer.
Behaviour is a part and parcel of every new round of chemotherapy which a cancer patient undergoes. Suppose a stimulus given during chemotherapy causes a negative reaction to the body, let’s say nausea. So, this patient will have excessive nausea during the therapy process. Now, if this patient undergoes behaviour modification, then his/her behaviour change (= not having nausea or having less nausea) will help in the next round of chemotherapy. So, development of cancer will be reduced.
Please note that behaviour change has been particularly useful in development of melanomas.