Heat and work are dependent variables because the amount depends on the pathway you take. is considered a state function, because the pathway does not affect the amount.

a)Heat and work are PATH dependent variable  

Path depended variable are those which in order to make a change in the system are concerned about the amount of heat or work transferred or moved in or out of the material within the system or the system as a whole. These variables are not depended on the state of the material before and after the process and but are dependent on the path followed during the process to bring change in the system.  

b)INTERNAL ENERGY, ENTROPY AND PRESSURE of the system are state function. These functions depend on the only on the initial and final state of the system or material and are not dependent on the path followed.  

oxygen +1 most likely