An average person consumes about 2000 Cal per day. A physics professor (80 kg) is too fond of donuts and consumes a 400 Cal apple fritter daily in additional to the 2000 Cal. If the professor is to maintain the 2000Cal by climbing stairs, how many vertical meters must he/she climb? Ignore any forms of friction.

(a) 25 m

(b) 125 m

(c) 1250 m

(d) None of the above