The correct answer to the question about which forest type covers the highest percentage of the world`s forest area is Temperate Coniferous Forests.

Here`s a quick explanation of each option:

1. Temperate Coniferous Forests: These forests exist in temperate regions and are characterized by trees like pines, cedars, and firs. They occupy massive land areas worldwide, especially in North America, Europe, and Asia.

2. Temperate Deciduous Forests: Though widespread, these forests characterized by trees losing leaves in the autumn and winter seasons don`t cover as much area as temperate coniferous forests.

3. Tropical Monsoon Forests: These forests are specific to regions that experience monsoon climates, primarily certain parts of Asia and Africa. They are relatively less widespread globally.

4. Tropical Rain Forests: These are important for biodiversity and are primarily found in equatorial regions. Despite their significance, their global spread is less than that of temperate coniferous forests.

So, among all these forest types, temperate coniferous forests cover the highest percentage of forest area in the world.