He designed numerous weapons, including missiles, multi-barreled machine guns, grenades, mortars, and even a modern-style tank.
He drew the line, however, with his plans for an underwater breathing device, which he refused to reveal, saying that men would likely use it for "evil in war.'

Read the passage above, what modern day device do you visualize when reading the bold print in the passage above?

A. Wet Suit
B. Scuba gear
C. Fins
D. Mask and Snorkel ​