Structure that indicate .....?

All of the above.

Anticlines (tectonic activity): in many plays hydrocarbons accumulate at the structural apex of an anticline.
Salt domes (depositional and tectonic activity): in many instances, traps form in sedimentary layers adjoining salt formations.
Reef carbonates (depositional and tectonic activity): a fractured carbonate rock can act as a good reservoir rock. hydrocarbons fill the space following fracturing!
Sand body lenses (depositional): typical reservoir rock. hydrocarbons fill the pore space in clean sandstones. usually surrounded by more muddy material, like when a sandy turbidite deposit ( lense)is surrounded by muddier marine layers.
unconformity (depositional) depositional trap. following a tectonic uplifting episode, when material is eroded and a subsequent subsidence episode when material is deposited again. the boundary between pre uplift deposition and syn subsidence deposition is an unconformity, with different depositional settings, and a potential for a cap rock (necessary in a play)

Thank you a lot, it helped