Answer:
XLSB
Explanation:
It is certainly the XLSB, as in this case the data is stored in the binary format, and hence it can ensure much fast accessing of the file. Also, you are free to use all the formulas, and the file size is around 16384 COLUMNS and 1048576 ROWS. And it supports various types. Hence, the XLSB can ensure most memory effective storage of the data, and it does ensure very fast file access as well as the use of all the formula also as stated.
