Regex to match a listing

I’m trying to find a regex that will match a list pattern like:

A. banana
B. potato
C. apple

or

1. banana
2. potato
3. apple

even if the list doesn’t start with A or 1 like:

q. banana
r. potato
s. apple

can I get some help with this please?

EDIT: the regex should match only orders with alphanumeric characters, for example, this shouldn’t get matched:

$. banana
&. apple
//or
b. banana
a. apple


Source: stackoverflow-php