Ryan also found that he could model the height of his plant with the equation h = 0.5d + 4, where d is the number of days and h is the height in centimeters. Which statement is true about the relationship between the height of the plant and the number of days?
A. This relationship is not a function because the plant can only be one height at a time.
B. This relationship is a function because the plant can only be one height at a time.
C. This relationship is a function because the plant can be more than one height at a time.
D. This relationship is not a function because the plant can be more than one height at a time.