Sure, let's break down the given algebraic expression \(14a - 72r - c - 34d \) and determine the coefficient of the \( c \)-term.
1. Identify the \( c \)-term in the expression. The given expression is \( 14a - 72r - c - 34d \).
2. Notice that each term in an algebraic expression consists of a coefficient (numerical factor) and a variable part. For example, in the term \( 14a \):
- The coefficient is 14.
- The variable part is \( a \).
3. Similarly, for the \( c \)-term, we see it as \( -c \). The presence of the minus sign indicates that the coefficient of \( c \) is negative.
4. The coefficient of a variable is the number that multiplies the variable. In the \( c \)-term (\( -c \)), we can rewrite this as \( -1 \cdot c \) to make the coefficient explicitly visible.
Thus, the coefficient of the \( c \)-term is \( -1 \).
Therefore, the correct answer is:
[tex]\[ -1 \][/tex]