Identify the incorrect word/phrase in the following:While (a)most people would not think (b)of starting a garden on their roofs, human beings (c)have been planting gardens on rooftops for (d)thousand of years.

Identify the incorrect word/phrase in the following:While (a)most people would not think (b)of starting a garden on their roofs, human beings (c)have been planting gardens on rooftops for (d)thousand of years.

• a (Incorrect)
• b (Incorrect)
• c (Incorrect)
• d (Correct)