Engineered herpes viruses are being used to treat cancer because the virus a. was engineered as an oncovirus, only infecting tumor cells. b. destroys the blood vessels feeding the tumor. c. prevents apoptosis. d. marks the location of tumors for surgical removal

a. was engineered as an oncovirus, only infecting tumor cells

Explanation:

Now-a-days a lot of onco-viruses are in development to fight cancer. These viruses are engineered specifically to target tumor cells. They reside in tumor cells and can be used as marker where they elicit very potent immune responses by antigen representations necessary for activation and recognition of tumors by immune system itself.

a. was engineered as an oncovirus, only infecting tumor cells.

Explanation:

Oncoviruses such as the engineered herpes virus is used a tool for killing cancer/tumor cells. When a virus infects a cancer cell, it makes several copies of itself within the cancer cells until the cell burst. The oncoviruses only target tumor cells, it does not affect healthy normal cells.

In addition to infecting tumor cells, it also triggers the immune system against the cancers.  

explanation:

for example, code 28039 - excision, tumor, soft tissue of foot or toe, subcutaneous, 1.5 cm or greater, appears before 28043 - excision, tumor, soft tissue of foot or toe, subcutaneous; less than 1.5 cm.

answer: apply a medicine

explanation: