Please provide a justification for adopting access control, mentioning if using public or private keys is relevant. A string: What precisely is it? Please give an illustration of a String. When we use the term "String Concatenation," what precisely do we mean? Give an instance. Can you give any examples of how to concatenate a String with other fundamental data types?

2. Write about reader process in mutual exclusion with help of an example program.

Answer the given question with a proper explanation and step-by-step solution.

Q1. Implement regular expression matching with support for '.' and '*'. '.' Matches any single character.'*' Matches zero or more of the preceding element. The matching should cover the entire input string (not partial). The function prototype should be:bool is_match(const char *s, const char *p) Some examples:is_match("aa","a") → falseis_match("aa","aa") → trueis_match("aaa","aa") → falseis_match("aa", "a*") → trueis_match("aa", ".*") → trueis_match("ab", ".*") → trueis_match("aab", "c*a*b") → true""" def is_match(str_a, str_b):    """Finds if `str_a` matches `str_b`     Keyword arguments:    str_a -- string    str_b -- string    """    len_a, len_b = len(str_a) + 1, len(str_b) + 1    matches = [[False] * len_b  for _ in range(len_a)]     # Match empty string with empty pattern    matches[0][0] = True     # Match empty string with .*    for i, element in enumerate(str_b[1:], 2):        matches[0][i] = matches[0][i - 2] and element == '*'     for i, char_a in enumerate(str_a, 1):…