Arrange the sentences in the most logical order to form a coherent paragraph. From the given options choose the most appropriate option.
i. The last thing airline pilots need is an additional hazard caused by Unmanned Aerial Vehicles (UAVs) weighing as much or more than a Canadian goose.
ii. In 2009 a collision with a flock of migratory Canadian geese caused a US Airways flight to suffer complete loss of power after take-off from LaGuardia airport, New York.
iii. The bird strike could have easily ended in disaster but for the skill of the pilot. Captain Chesley Sullenberger, who famously brought the stricken Airbus A320 down for a splash landing in the Hudson River without loss of life.
iv. One of the most feared birds encountered by aircrafts is the common Canadian goose, weighing anything up to 6 kg.

To form a coherent paragraph, the sentences should flow logically, building a clear narrative or argument. Sentence iv introduces the Canadian goose as a significant threat to aircraft, providing context about its weight and danger. Sentence ii then gives a specific example of this danger, describing the 2009 US Airways incident involving a collision with Canadian geese. Sentence iii follows naturally, explaining the outcome of that incident and highlighting the pilot’s skill in averting disaster. Finally, sentence i concludes the paragraph by connecting the earlier example to a broader point about the additional hazard posed by UAVs, which could be as heavy as or heavier than a Canadian goose, reinforcing the overall concern for airline safety.

The most logical order is: iv (introducing the Canadian goose), ii (an example of a bird strike), iii (resolution of the example), and i (broader implications with UAVs). This matches option a: iv, ii, iii, i.