Refer to the Table

Multiple Choice

Refer to the table.
The table contains data on the effects of a symbiosis between a bee (host) and a bacterium over 22 years. The table shows the upper and lower bounds for the effects of the association; positive numbers denote net benefits and negative numbers denote net costs. (If zero is between the upper and lower bounds, consider the effect to be zero, since it is statistically indistinguishable from zero.) According to the table, this interaction first become a commensalism in

A) 1993.
B) 1997.
C) 2001.
D) 2005.