Excel: If Formula containing Text longer than 255 characters

I am setting up an if statement in Excel. The text is much longer than 255 characters. If a statement from a drop down list is selected, I want a string of text to appear in the next column. The formula for joining all the different text that can appear is

=C1&C2&C3&C4&C5&C6&C7&C8&C9&C10&C11&C12&C13&C14&C15&C16&C17

So there are 17 different choices in the drop down list and 17 different strings that should appear in the next column. I only need 1 string of text to appear in the right column for each choice in the drop down list. However, Once a selection is made from the drop down list, it also includes a “false” for each of the string that doesn’t match the drop down list.

How can I get rid of the 16 false statements?