Which of the following is a drawback to analyzing algorithms by proving O$-$ upper bounds on the worst case? $($Birden $$ok se$$enek i$$aretlenebilir$.)$

$1$ point

a$-$ Generally cannot be used to compare algorithms.

b$-$ Likely to be too much detail in the analysis.

c$-$ Generally cannot be used to predict performance.

d$-$ Input model may be unrealistic.