Which mission is known for investigating Mars using an orbiter and a lander?

The mission renowned for investigating Mars through both an orbiter and a lander is the Viking program. Launched in the 1970s, the Viking program comprised two space missions, Viking 1 and Viking 2. Each mission included both an orbiter, which studied Mars from above, and a lander, which conducted experiments on the Martian surface. The orbiter gathered atmospheric data and high-resolution imagery of the planet's surface, while the landers performed various experiments designed to assess the physical and chemical properties of the soil and the potential for life on Mars.

This dual approach of having both an orbiter and a lander allowed for comprehensive data collection, making significant contributions to our understanding of the Martian environment and geology. The Viking program was a landmark in planetary exploration, paving the way for future missions. The other choices - Mariners, Surveyors, and Pioneers - are associated with different planetary missions or objectives, but they did not combine both an orbiter and a lander for Mars specifically like the Vikings did.