Final answer:
The opposite temperature of 1 degree above zero is 1 degree below zero, which is represented by option (c).
Step-by-step explanation:
To find the opposite temperature of Tuesday's temperature, which was 1 degree above zero, we should look for the temperature that has the same magnitude but is on the opposite side of the temperature scale. The opposite of 1 degree above zero (positive 1) is 1 degree below zero (negative 1). So, the answer is c) 1 degree below zero.