What will be the output of the following Python code?

a = re.compile('0-9')
a.findall('3 trees')

A. A sequence of characters that defines a search pattern B. A built-in function C. A mathematical expression D. A special data type

A. It compiles a regular expression pattern into a regular expression object B. It converts strings to regular expressions C. It defines a new class D. It imports the re module

A. re B. regex C. pyregex D. none of the mentioned

A. By using the re module B. By using the regex keyword C. By including it as a string D. By using the regx function