This question requires analyzing the characteristics of isotherms in different hemispheres and over different surfaces (land vs. ocean).

Analyzing Isotherm Statements

Statement A: Isotherm Regularity

Statement A claims isotherms are more regular in the Southern Hemisphere than the Northern Hemisphere.

• Reasoning: The Southern Hemisphere has a larger proportion of ocean surface compared to land. Oceans moderate temperature changes, leading to smoother, more gradual temperature gradients. The Northern Hemisphere has more extensive landmasses, which experience greater temperature extremes between seasons and day/night cycles, causing isotherms to bend more sharply.
• Conclusion: Statement A is true.

Statement B: Northern Hemisphere Isotherm Bending

Statement B describes the seasonal bending of isotherms over continents in the Northern Hemisphere.

• Reasoning: In July (summer), continents heat up more than oceans, causing isotherms to bend northward over land to reflect higher temperatures. In January (winter), continents cool down more than oceans, causing isotherms to bend southward over land to reflect lower temperatures. The statement reverses this pattern.
• Conclusion: Statement B is false.

Statement C: Temperature Extremes (Land vs. Ocean)

Statement C asserts that warmest temperatures are always over land and coldest over oceans.

• Reasoning: While continents generally experience greater temperature *ranges* (hotter summers, colder winters) than oceans, the statement uses absolute terms ("always"). Equatorial oceans can be consistently very warm. Furthermore, the coldest temperatures recorded on Earth occur over continental landmasses (like Antarctica and Siberia), not oceans.
• Conclusion: Statement C is false.

Determining the Correct Option

Based on the analysis:

• Statement A is true.
• Statement B is false.
• Statement C is false.

Therefore, the correct option is the one stating that A is true, and B and C are false.