Critical Reasoning

According to a recent magazine article, of those office employees who typically work 8 hours at the office each day but sometimes say that they will work at home on a particular day, 25 percent actually work less than one hour. At the same time, over 90 percent of those same office employees believe they are more productive working at home than working in their office.

The statements above, if true, best support which of the following conclusions about the office employees discussed in the article?
a) On average, the office employees working at home for a day work fewer hours than office employees working at the office.
b) 10 percent of the office employees are less productive working from home than working in their office.
c) At least 15 percent of the office employees do not define productivity exclusively in terms of the number of hours worked.
d) At least 25 percent of the office employees can complete the same amount of work in one hour at home as in 8 hours at the office.
e) Some of the office employees make statements regarding their productivity that are not in fact true.

Please explain... i guessed it as C but i don't know how to substantiate that... i just did a process of elimination... explain how to solve this... thanks

Premise 1. 25% of employees who say they will work at home actually work less than one hour at home, compared to their normal 8 hours at work.

Premise 2. 90% of those employees believe they are more productive at home.

Clearly, based on the numbers alone, that doesn't make any sense. However, if, as in C, employees are using other criteria to judge productivity, then the statements make sense together.

a) We have no information about other workers who only work in the office
b) No information about this
d) We have information about 25 percent of employees, so drawing a conclusion about more than 25% is unsupported
e) Probably true , but we have no way of supporting this

I posted an explanation here:

https://www.beatthegmat.com/productivity-t92834.html