Abeaker contains 0.42l of water. the volume of water is milliliters.

The problem given above is simply a conversion problem. We are asked to convert from units of liters to units of milliliters. To do this, we need a conversion factor which would relate the different units involved. We either multiply or divide this certain value to the original measurement depending on what is asked. From literature, we will find that 1 Liter is equal to 1000 milliliters. So, we have to multiply 1000 to the original value given. We do as follows:

0.42 L ( 1000 mL / 1 L ) = 420 mL

Therefore, the volume of water in the beaker is 420 mL.

Most likely a is the answer - because  you generate   38 atp's but also consume an atp.   each atp gives approx. less than 4 kcal so probably a is the closest answer.