Scenario Biomedical Scientists Have Recently Developed an Anticancer Drug Delivery System

Scenario
Biomedical scientists have recently developed an anticancer drug delivery system that sneaks the anticancer drug into cancer cells before releasing it. They were able to do this by using two sets of liposomes. An anticancer drug (Doxorubicin (Dox) ) bound to DNA molecules was added into one set of liposomes, and a high concentration of ATP molecules were added to the other set of liposomes. The drug is inactive when bound to DNA molecules. Researchers inject both types of liposomes into cancer cells, and upon doing so their contents are released. The ATP molecules from one set of liposomes bind to the DNA molecules from the other set of liposomes) and activate the drug, thus inducing cell death and decreasing tumor size.
Mice with breast cancer tumors were treated with this liposome system to test the effectiveness of the drug. The scientists performed three trials-one with both types of liposomes (Dox + ATP) , one with just the drug (Dox only) , and one with a salt solution (control) . Examine the figure below and answer the following questions.
-Which statement regarding these data is TRUE?

A) The weight of the tumors did not change if treated with just the drug (Dox only) or both types of liposomes (Dox + ATP) .
B) Tumor weight decreases when you add just the drug (Dox only) to cancer cells.
C) Adding just the drug (Dox only) or both types of liposomes (Dox + ATP) results in similar decreases in tumor weight.
D) Dox must be entering the cancer cells via endocytosis to induce cell death.