The answer is A.
Hydroelectric, which is usually generating electricity through use of a dam.
Solar, energy from the Sun.
Biomass, organic material formed from plant matter.
To answer this item, it is assumed that the gas in the cylinder is ideal such that it follows the equation,
PV = nRT
when V is to be calculated,
V = nRT/P
V = (4)(0.0821 L.atm/molK)(300 K) / (400 kPa/101.325 kPa/atm)
V = 24.95 L
Thus, the volume of gas in the cylinder is 24.95 L.
The elements required for a fire to start are
oxidizing agent, heat, and fuel.
The oxidizing agent is usually oxygen - when there is a lot of air, of oxygen, a fire can broke out more easily if the conditions are right - if there is no oxygen, the fire won't start - we put out a fire by depriving it of oxygen. Next, you need some heat and fuel to start a fire, which can all be seen in this triangle.
The gravitational force between two masses is given by:

where
G is the gravitational constant
m1 and m2 are the two masses
r is the separation between the two masses
We see that the force is proportional to the inverse of the square of the distance:

therefore, if the distance is tripled:
r'=3r
The force decreases by a factor 1/9:

Since the original force was 36 N, the new force will be