Saitama and Boros must find people with salary 30000 or more from two tables. Boros used a conditional statement but took more time; Saitama suggested creating another file. What is the trade-off of Saitama's solution?

• aIt is slower and uses less data entry
• bIt makes the process faster but requires more data entry time
• cIt deletes the original data
• dIt removes the need for any query