The ras proto-oncogene can become an oncogene by a single point mutation that alters its protein product to have activity.
a. more gtpase
b. less nucleotide exchange
c. greater nucleotide exchange
d. constitutive raf-activation

The correct answer is D.

Explanation:

The Ras Proto-Oncogene is a gene found in normal cells, which by the single point mutation mentioned in the question, can turn into Oncogene. Because Proto-Oncogene is a gene that controls and regulates the division of the cell, a mutation in this gene leads to uncontrolled cell divisions which then leads to cancer. The correct answer is D since RAF-Activation describes "Rapidly Accelerated Fibrosarcoma, fibrosarcoma being a cancer which affects fibrobalst cells.

I hope this answer helps.

cancer   is   essentially   uncontrolled   mitosis   of specialized cells

lysosome is this part of the cell is surrounded by a very thick outer membrane to protect the rest of the cell from its strong enzymes.