..........................

( 3ab / 2c ) ÷ ( 9b² / 4ac )

= ( 3ab / 2c ) × ( 4ac / 9b²)

= ( 3ab ) ( 4ac )
-----------------------
( 2c ) ( 9b² )

= 12a²bc
---------------
18b²c

= ( 6bc ) ( 2a² )
-----------------------
( 6bc ) ( 3b )

= 2a²
---------
3b

( A )