Final answer:
The function model for the growth of Botryococcus braunii is y = 50(3)^x for x ≤ 15.
Step-by-step explanation:
Option a) The rule of the function model is y = 50(3)^x for x ≤ 15.
This statement is correct. The function model represents the growth of the Botryococcus braunii algae over time. The initial dry weight of the algae is 50 mg/L, and under specific conditions, the algae triples every three hours for the first 15 hours of growth. The function y = 50(3)^x accurately represents this exponential growth, where x represents the time in hours and y represents the dry weight of the algae.