The correct answer is: Brian Lara.
Brian Lara scored 501 not out for Warwickshire against Durham in 1994. This is the highest individual score in first-class cricket.
Hanif Mohammad scored 334 not out for Pakistan against West Indies in 1958. This was the highest individual score in first-class cricket for 36 years, until Lara broke it.
Sir Donald Bradman scored 334 for Australia against England in 1930. This was the highest individual score in first-class cricket for 29 years, until Hanif Mohammad broke it.
Sachin Tendulkar scored 249 not out for India against South Africa in 2003. This is the highest individual score by an Indian batsman in first-class cricket.
In conclusion, Brian Lara scored the most runs in a single first-class innings. He scored 501 not out for Warwickshire against Durham in 1994. This is the highest individual score in first-class cricket.