CORRECT!

Before the first flight of the day, the pilot should perform a complete pre-flight inspection of the aircraft, using a checklist based on the aircraft manufacturer's recommendations and personal experience. Each item should be checked in the order in which it appears in the checklist to ensure that no items are overlooked. This sort of systematic, item-by-item check of the aircraft, its component parts and critical systems will help to ensure the safest possible operation.

So, you've performed the comprehensive pre-flight inspection, conducted the first leg of the day's flight plan safely by operating to a Class C airport some 230 nautical away from your home base. It is now time to consider the return flight. The aircraft has been sitting on the apron of the general aviation FBO for the last 3 1/2 hours while you conducted your off-airport business. You pay your fuel bill and leave the FBO office and walk out to the aircraft. You are in a hurry to beat the storm front which is rapidly approaching the airport, so you unlock the cabin door, hop in, buckle up, start the engine, get your departure clearance, taxi to the assigned runway and take off. About 35 minutes into the flight, you glance at your fuel guage and wonder why the right tank is reading almost empty. It was just topped off at the departure airport, but you were busy and didn't have the chance to oversee the refueling process so you didn't see the attendant leave the cap off the right fuel tank. Fortunately, the cap fell off the airframe during the taxi for departure and didn't hit the fuselage during flight, but now you have a fuel emergency to deal with.

This situation could have been prevented by a walk-around inspection before flight, checking for items like fuel levels (were they really topped off?) and fuel caps (were they replaced properly?) as well as other things, like determining if the airframe sustained any damage while it was parked (vehicular damage, debris blown into the airframe by another aircraft's prop wash, etc). A walk-around takes about 3 minutes, well worth the effort to help ensure the safest possible operation.