In 2009, why was 13-year-old Nischal Narayanam of Hyderabad given an entry into the Guinness World Records?

For adding the most number of randomly picked five digit numbers in one minute

For memorising most number of random objects in one minute

For memorising the value of pi to the maximum number of digits after decimal

For memorising most numbers in sequence in one minute

For multiplying two six digit numbers in the fastest time