I think d would be the answer.
Answer:
1 m = 39.37 in = 39.37/12 ft = 3.28 ft
V = 1145 k/hr = 1145k/hr * 6076 ft/k = 6957020 ft / hr
V = 6957020 ft/hr / 3600 s/hr = 1933 ft/sec
V = 1933 ft/sec / (3.28 ft / m) = 589 m/s
Check:
88 ft/sec = 60 mph
(1145 k/hr * 6076 ft / k) 3600 sec/hr = 1933 ft/sec = 589 m/s
1933 ft/sec / (88 ft/sec) * 60 mph = 1318 mph
Also, 1318 / 1145 = 6076 / 5280 as it should
I believe the answer would be mass. Low mass stars and medium mass stars often become white dwarfs when they die while high mass stars explode in violent explosions called supernovas and usually leave behind a black hole or a neutron star.