The Essential Difference Between Malignant and Benign Tumours Is That

The essential difference between malignant and benign tumours is that ________.

A) malignant tumours grow three times faster than benign tumours
B) malignant tumours never lead to death, while benign tumours always do
C) malignant tumours produce metastases and/or invade neighboring tissues, while benign tumours do not
D) benign tumours produce metastases and/or invade neighboring tissues, while malignant tumours do not