How do you determine the best "big-Oh" form?

Use the results of Table 1 to determine the best “big-Oh” form for the following function f: Z^+→ R.

f(n) = 3n + 7

Table 1 (I'm not sure how to write tables so I used the dash (-----):

Big-Oh Form ------------------------ Name

O(1) --------------------------------- Constant

O(log_2 n) -------------------------- Logarithmic

O(n) --------------------------------- Linear

O(n log_2 n) ------------------------ n log_2 n

O(n^2) ------------------------------ Quadratic

O(n^3) ------------------------------ Cubic

O(n^m), m = 0, 1, 2, 3,... ------- Polynomial

O(c^n), c > 1 ----------------------- Exponential

O(n!) -------------------------------- Factorial