In which of the following process (es), work done is Zero?

In which of the following process (es), there is no change in the internal energy of the system?

In which of the following cases is the work done positive or zero or negative ? Work done by force of gravity on a ball thrown up vertically up into the sky.

In which of the following cases is the work done positive or zero or negative ? Work done by the porter on a suitcase in lifting it from the platform on to his head.

In which of the following cases is the work done positive or zero or negative ? Work done by the force of gravity on suitcase as the suitcase falls from porter's head.

In which process net work done is zero ?