Help with geology question?

Stellar Nursery – Pillars of Creation, Eagle Nebula. The Pillars of Creation are large, dense masses of dust and interstellar gas (mostly molecular hydrogen) that rise from the stellar nursery of the Eagle Nebula (M16). Here, dense pockets of dust and gas collapse in on themselves to form young stars. The Pillars of Creation are located about 6,500 light-years from Earth, and the left-most pillar has a current length of approximately 4 light-years (a light-year is the distance light travels in one year...about 9.5 trillion km). What is the length of the left-most pillar (in km)?

Choose one:

 ~13.5 trillion km

 ~38 trillion km

 ~9.5 trillion km

 ~2.375 trillion km