I think the answer is b. easy to digest.
C. and D. are chemical properties,
Absolute, Atmospheric, Differential, and Gauge Pressure
Answer:

Explanation:
When the rock is immersed in unknown liquid the forces that act on it are shown as under
1) Tension T by the string
2) Weight W of the rock
3) Force of buoyancy due to displaced liquid B
For equilibrium we have 
=
When the rock is suspended in air for equilibrium we have

When the rock is suspended in water for equilibrium we have
+
=
Using the given values of tension and solving α,β,γ simultaneously for
we get

Solving for density of liquid we get


Answer:
4.3 x 10^16 kg
Explanation:
M = rv^2/G =[90,000 x 5.66^2] / [6.67 x 10^-11]
M = 43,226,446,776,611,694 = 4.3 x 10^16 kg - Ida's mass.