Which of the following birds is generally regarded in general knowledge references as the fastest of all birds in sustained flight?

Introduction / Context:
This question is about speed records in the bird world. Many exams ask about the fastest bird, tallest bird or largest flying bird. Although scientific discussions distinguish between diving speed and level flight speed, general knowledge books often highlight one bird as the fastest in sustained flight. Recognising which bird this is helps you answer a common superlative type question quickly.

Given Data / Assumptions:

• The question asks for the fastest of all birds as presented in typical GK references.
• The options include blood pheasant, swift, sparrow, none of these and ostrich.
• We assume the question refers to fastest flying bird in level or sustained flight, not fastest runner on land.
• The expected answer follows common exam convention rather than the most technical scientific ranking.

Concept / Approach:
In many general knowledge books, the swift, particularly the common swift, is listed as the fastest bird in level flight because it can maintain very high speeds for long periods. The peregrine falcon is often cited as the fastest bird in a diving stoop, but that specific bird is not among the answer choices here. Ostrich is the fastest running bird on land, not in flight. Therefore, when exam questions ask simply for the fastest bird without detailed qualifiers and present swift as an option, swift is usually the intended correct answer for flying speed.

Step-by-Step Solution:
Step 1: Interpret the question as referring to flying speed rather than running speed, since it is about birds in general. Step 2: Recall that many GK tables list swift as the fastest bird in sustained flight. Step 3: Recognise that ostrich, while fast, is famous for running, not flying, and therefore does not match the context of flying speed. Step 4: Blood pheasant and sparrow are not commonly associated with any top speed record. Step 5: Since swift appears and fits the standard GK statement, choose swift as the correct answer rather than none of these.

Verification / Alternative check:
If you consult exam focused GK material, you will often find lists stating fastest bird in flight equals swift and fastest bird on land equals ostrich. Some advanced texts refine this by distinguishing dives, where peregrine falcon dominates, but such detail rarely appears in simple MCQs. Because the option swift appears explicitly, and aligns with common teaching, it is safe to mark swift as the intended answer here.

Why Other Options Are Wrong:
Blood pheasant is a Himalayan bird valued for its beauty but is not recorded as the fastest bird.
Sparrow is a small common bird with modest flying speed and agility but not a speed record holder.
None of these would only be correct if no option matched standard GK, but swift clearly does, so this choice is inappropriate.
Ostrich is the fastest running bird on land and is flightless, so it cannot be the fastest bird in flight.

Common Pitfalls:
Some students recall that peregrine falcon is the fastest bird in a dive and become confused when it is not among the options, leading them to incorrectly choose none of these. Others may be distracted by ostrich because they remember it as a fastest bird in another context. To avoid such errors, keep separate mental associations: swift for fastest bird in sustained flight and ostrich for fastest running bird, while peregrine falcon dominates in high speed dives.

Final Answer:
In general knowledge references, the bird regarded as the fastest of all in sustained flight is the swift.