Which of the following SQL queries counts the number of occurrences for each value of the field order_type in the table orders?
A . SELECT order_type,COUNT(*) FROM orders WHERE order_type=order_type;
B . SELECT order_type,COUNT(*) FROM orders GROUP BY order_type;
C . COUNT(SELECT order_type FROM orders);
D . SELECT COUNT(*) FROM orders ORDER BY order_type;
E . SELECT AUTO_COUNT FROM orders COUNT order_type;
Answer: B