AMO 2027 Grades 9-11 SET 1 - Self-study Question 7

Six boys of differing heights are arranged in 2 rows of 3 each. Each boy is taller than the boys in front of him and also taller than the boys to his left. How many arrangements for the six boys are possible?

Interpretation used in the source: height increases from front to back in each column, and from left to right in each row.

Choose one option.