Final answer:
The function for the arithmetic sequence is f(n) = -3 - n.
Step-by-step explanation:
An arithmetic sequence is a sequence of numbers in which the difference between consecutive terms is constant. In this case, the common difference is -1.
To find the function for this arithmetic sequence, we can use the formula f(n) = a + (n-1)d, where f(n) is the nth term of the sequence, a is the first term, and d is the common difference.
Given that f(1) = -3 and the common difference is -1, we substitute these values into the formula to get f(n) = -3 + (n-1)(-1). Simplifying this expression, we get f(n) = -3 - (n-1) = -3 - n + 1.
Therefore, the function for the arithmetic sequence is f(n) = -3 - n, which corresponds to option A.