What is the value of (32 cos6x – 48 cos4x + 18 cos2x – 1)/[4 sin x cos x sin (60 – x) cos (60 – x) sin (60 + x) cos (60 + x)] ?

• 4 tan 6x
• 4 cot 6x
• 8 cot 6x
• 8 tan 6x