The Basic Conjoint Analysis Model Expressing the Fundamental Relationship Between

The basic conjoint analysis model expressing the fundamental relationship between attributes and utility in conjoint analysis is shown below: What does ki represent?
U(X) =
M
Σ
I=1
Ki
_Σ ^αij^Xij j=1

A) 1 if the jth level of the ith attribute is present, or 0 otherwise
B) the part- worth contribution or utility associated with jth level (j, j=1, 2, ...k_i) of the ith attribute (i, i=1, 2, ...m)
C) number of attributes
D) number of levels of attribute i