Step 1: List the two physical properties that matter here.
We need to think about density, which gravity surveys pick up, and electrical conductivity, which resistivity surveys pick up, for the minerals that make up a VMS deposit.
Step 2: Note the density of massive sulphides.
Ore minerals like pyrite and chalcopyrite are heavier per unit volume than ordinary volcanic rock. A heavy buried body raises the pull of gravity right above it, so we expect a high, positive, gravity anomaly.
Step 3: Note the conductivity of massive sulphides.
These same sulphide minerals conduct electricity very well, far better than the silicate rocks around them. A good conductor resists the flow of current very little, so the resistivity reading over the deposit drops, that is, resistivity is low.
Step 4: Put the two clues together.
A dense, highly conductive ore body gives high gravity paired with low resistivity, not any of the other three combinations.
Step 5: Conclude.
\[ \boxed{\text{High gravity and low resistivity}} \]