Four buses were filled with children and 20 children rode in cars for a field trip. Write an expression for how many children went on the field trip. A. \( 4 c \) B. \( 4 b+20 c \) C. \( 20 c \) D. \( 4 c+20 \)

To determine how many children went on the field trip, we need to consider the number of children on the buses and the number of children who rode in cars. Let \( c \) represent the number of children on each bus. Since there are 4 buses, the total number of children on the buses would be \( 4c \). Additionally, there are 20 children who rode in cars. To find the total number of children who went on the field trip, we can add the number of children on the buses to the number of children in cars: \[ \text{Total children} = 4c + 20 \] Thus, the correct expression for how many children went on the field trip is: **D. \( 4c + 20 \)**.