Step 1: Define the two property types.
An intensive property does not depend on how much matter is present, while an extensive property scales with the amount of matter.
Step 2: A simple test.
Imagine splitting the sample in two; if the value stays the same it is intensive, if it halves it is extensive.
Step 3: Check surface tension.
Surface tension is set by intermolecular forces and is the same for a drop or a lake, so it is intensive.
Step 4: Check heat capacity.
Heat capacity is the total heat needed to warm the whole sample by one degree; double the sample and you need double the heat, so it depends on amount and is extensive.
Step 5: Check viscosity.
Viscosity depends on temperature and molecular structure, not the quantity, so it is intensive.
Step 6: Check temperature.
Split a uniform body and both halves stay at the same temperature, so temperature is intensive.
Step 7: Pick the odd one.
Only heat capacity scales with amount, so it is the non-intensive property, option (2).
\[ \boxed{\text{Heat capacity is extensive}} \]