In world bridge engineering, which of the following is often listed in general knowledge sources as the highest bridge in the world by deck height?

Introduction / Context:
This question checks awareness of notable world bridges often mentioned in competitive exam material. Bridges can be compared by total length, span length or height above the ground or river below. The question asks specifically about the highest bridge in the world, which usually refers to deck height above the valley or river. In many general knowledge references, the Sidu River Bridge in China is listed as the highest bridge by deck height, even though later projects may slightly surpass it. The expected exam answer therefore follows those widely used GK compilations.

Given Data / Assumptions:

• We are concerned with bridge height above the surface below, not total length of the structure.
• Options include Millau Viaduct, Sidu River Bridge, Bailey Bridge and None of these.
• We assume the exam follows the standard GK listing where Sidu River Bridge holds the record.
• Bailey Bridge refers here to a type or a specific high altitude bridge in India, but not the world record holder in deck height.

Concept / Approach:
To choose the correct option, one must recall which bridge general knowledge books associate with the phrase highest bridge in the world. The Sidu River Bridge in China spans a deep gorge and has an impressive deck height, which led to its frequent appearance in GK lists. Millau Viaduct in France is very tall and often highlighted for its tall pylons, but its deck stands over a less deep valley compared to the Sidu River gorge. Bailey Bridge is known more as a type of portable truss bridge and for a high altitude installation in Ladakh, not as the global height record holder. Therefore, Sidu River Bridge matches the conventional exam key.

Step-by-Step Solution:
Step 1: Focus on the phrase highest bridge, which relates to deck height above the ground or water below. Step 2: Recall that Sidu River Bridge in China is widely described in GK books as the highest bridge in the world. Step 3: Remember that Millau Viaduct is very tall but is usually listed as the tallest road bridge in Europe, not necessarily the highest by deck height worldwide. Step 4: Recognise that Bailey Bridge is a well known type of modular bridge and a famous high altitude bridge but not the world height record holder. Step 5: Based on exam oriented memory, select Sidu River Bridge as the correct answer.

Verification / Alternative check:
An alternative check is to think of how question banks on longest and largest structures group these records. Under highest bridge, Sidu River Bridge is a recurring name, especially in material prepared for banking and civil services examinations. Millau Viaduct appears in separate lists that emphasise design and pylon height. If candidates can recall this pattern, it confirms that Sidu River Bridge is the intended answer, aligning with the way such questions are usually framed in competitive exam practice sets.

Why Other Options Are Wrong:
Millau Viaduct is a very tall bridge in France but is not typically named as the highest bridge by deck height in standard GK superlative lists used in exams. Bailey Bridge is famous as a type of military or modular bridge and for a high altitude bridge in Ladakh, but it is not the top global record holder for height. None of these is incorrect because one of the given options, Sidu River Bridge, is recognised in GK compilations as the correct record holder.

Common Pitfalls:
A common mistake is to confuse tallest pylons or towers with highest deck height and choose Millau Viaduct for that reason. Another error is over focusing on the Indian high altitude Bailey Bridge without checking global context. To avoid such confusion, aspirants should remember that the term highest bridge in most exam books points to the Sidu River Bridge and that world records are often summarised in dedicated tables that clearly indicate which structure holds each title.

Final Answer:
In general knowledge references used for competitive exams, the highest bridge in the world by deck height is usually given as the Sidu River Bridge in China.