Based on the code segment below and by using cstring and/or cctype functions, write C++ statements to perform each of the following instructions. Note that, each question is dependent. Important: Please write C ++ statements WITHOUT blank spaces unless it is absolutely needed. Example: int num,ab; char str1[10] = "always "; char str2[10] = "smile"; char str3[15]; int len; a) Concatenates str2 string to the end of strl string. b) Copy the resulting string in (a) into str3. c) Store the length of str3 into len. d) Converts str3 string to lowercase by filling in blanks in the code segment below with an appropriate statement. for (int x = 0; ; x++)