Near the London Eye, there is a bridge ____ the Thames River.

The preposition “over” is correct for the sentence “Near the London Eye, there is a bridge ____ the Thames River,” as it indicates the bridge spans above the river, a common usage for bridges. In English, “over” denotes crossing over a body of water. Options A (across, for surface crossing), C (along, parallel movement), and D (beside, next to) are less precise for a bridge’s position, making B the appropriate choice.