Answer : B
Explanation:
"still" means -- up to and including the present or the time mentioned.
"of course" means -- something that is obvious.
"any" means -- at all.
"especially" means -- specifically.
The construction of the sentence ("but") suggests us that the clause is contrasting.
Thus the most appropriate word for use from among the options is "still".
Therefore the complete correct sentence is:
I called Tom at 10:00 in the morning, but he was STILL in bed.