With reference to the planet Earth, consider the following statements: 1. Rain forests produce more oxygen than that produced by oceans. 2. Marine phytoplankton and photosynthetic bacteria produce about 50% of world's oxygen. 3. Well-oxygenated surface water contains several folds higher oxygen than that in atmospheric air. Which of the statements given above is/are correct?

States that more than half of the world's oxygen is produced by the oceans, labelling them the 'planet's lungs'.

A student could compare this claim to estimates of oxygen production by terrestrial forests (e.g., rainforests) to judge which is larger.

Says microalgae in water produce more than half of Earth's oxygen supply, highlighting the major role of microscopic marine photosynthesizers.

A student could use this to infer that marine primary producers (not just trees) contribute substantially and compare their productivity per area to rainforest productivity.

Notes oceans cover ~70.78% of Earth's surface and support total biomass possibly ten times that on land, implying a large capacity for photosynthesis.

Combine ocean area and high marine biomass with per-area productivity data (from outside sources) to estimate total oceanic oxygen production versus forests.

Explains that life (and oxygen production through photosynthesis) was long confined to the oceans and that oceans contributed oxygen to the atmosphere historically.

Use this historical pattern to reason that oceans remain a primary oxygen source today and weigh that against terrestrial forest contributions.

Describes the atmosphere as the principal reserve of available oxygen and highlights the ocean as Earth's major carbon pool, linking oceans to major biogeochemical cycles.

A student could infer that large carbon/stored nutrient pools in oceans support extensive photosynthetic communities, then compare expected oxygen fluxes with those from rainforests.