Final answer:
Option 3 from the given choices is the most effective because it clearly communicates the condition of The Bridge Foundation's grant to the Early Childhood Center, specifying the requirement for quarterly reports.
Step-by-step explanation:
The most effective way to combine the two sentences about The Bridge Foundation and the Early Childhood Center is to ensure that the condition of the grant is clearly and concisely communicated. Among the given options, choice number 3 is the most effective as it combines the two sentences while clearly stating the grant's condition. Thus, the revised sentence would read: The Bridge Foundation awarded the Early Childhood Center a grant with the one condition that the Center would be required to report back quarterly with parent and teacher surveys.