The pressure of a gas changes linearly with volume from \( A \) to \( B \) as shown in figure. If no heat is supplied to or extracted from the gas then change in the internal energy of the gas will be:
\( 4.5 \, \text{J} \)
\( 6 \, \text{J} \)
\( -4.5 \, \text{J} \)
zero