During which alignment of the Earth, moon, and sun do spring tides occur?

Spring tides occur when the Earth, moon, and sun are aligned in a straight line, which is the condition that leads to the highest tidal ranges. This alignment happens during both the new moon and full moon phases. When the sun and moon are aligned with the Earth, their gravitational forces combine to produce a stronger pull on the Earth's oceans, resulting in higher high tides and lower low tides, which characterizes spring tides.

The other scenarios do not create the same tidal effects. For instance, when the moon and sun are at right angles to each other, such as during the first and third quarter phases, the gravitational forces partially cancel each other out, leading to neap tides, where the tidal range is less pronounced. Similarly, a triangular formation does not imply a direct gravitational influence that would enhance tidal ranges, and while the term "opposition" typically refers to the moon being directly opposite the sun, it’s during the full moon when they are aligned rather than simply being in opposition. Thus, the correct answer focuses on the alignment which maximizes gravitational effects on tides.