Study the given table and answer the question that follows. The table shows the yearly production (in thousands) of scooters in five different factories (P, Q, R, S and T) from $1985$ to $1989$:



In which year was the production of scooters in all factories equal to the yearly average number of scooters produced from $1985$ to $1989$?

1. A
   $1986$
2. B
   $1985$
3. C
   $1988$
4. D
   $1987$