The question is asking about the highest speed at which a computer could perform operations as of December 1996.

Option 1 suggests the computer could perform 10^6 (1,000,000 or a million) operations per second. Option 2 suggests the computer could perform 10^9 (1,000,000,000 or a billion) operations per second. Option 3 suggests the computer could perform 10^12 (1,000,000,000,000 or a trillion) operations per second. Option 4 suggests the computer could perform 10^15 (1,000,000,000,000,000 or a quadrillion) operations per second.

As per the given answer, option 3 is correct, meaning that the computer was capable of performing a trillion (10^12) operations per second as of December 1996. The larger the exponent, the greater the speed. Thus, options 1 and 2 would represent slower speeds, while option 4 would represent a greater speed not possible in 1996.