The famous Royal Albert Bridge was built by Isambard Kingdom Brunel in the 1850's and regarded as one of his greatest railway bridges. Hence, Option A is correct. Among the rest of the options-
George Stephenson was a self-made mechanical engineer, largely credited with building the first railway line and becoming the 'father of the railways'.
James Watt was an inventor and mechanical engineer whose improvements in steam engine technology drove the Industrial Revolution.