The correct answer is C. Ali is bad at using computers but great at data entry.
Step-by-step explanation
The graph shows Ali's ratings in "Computer skills" and "Data entry skills" in which he rates from one (the lowest rating) to five (the highest rating). Ali has a result of "one" in "Computer skills" and five in "Data entry skills". According to the information provided by the graph, it can be established that Ali is excellent in the field of "Data entry skills" but his performance in "Computer skills" is poor, so the sentence that best reaffirms this information is C. Ali is bad at using computers but great at data entry. Also, this option is correct because uses the correct linking word of contrast "but", which makes the sentence grammatically correct.