Choose the option nearest in meaning to the word underlined.
His discovery of the vaccine became a quantum leap in search for a scientific cure for the illness.
A
victorious battle
B
slow but steady step
C
great impovement
D
fast but sure step
Verified Correct Answer: C.
Grammar & Contextual Explanation
Quantum Leap: a huge, often sudden, increase or advance in something.
Source: Myschool Past Questions Archive (Record #12099)