Write a recursive, int-valued function, len, that accepts a string and returns the number of characters in the string.
the length of a string is:
0 if the string is the empty string ("").
1 more than the length of the rest of the string beyond the first character.

Apresentation program is a software package used to display information in the form of a slide show. it has three major functions: an editor that allows text to be inserted and formatted, a method for inserting and manipulating graphic images, and a slide-show system to display the content.

Ithink the answer is a