The correct answer is (a) 0.69.
The average size of land-holding in Uttarakhand is 0.69 hectares. This means that the average farmer in Uttarakhand owns 0.69 hectares of land. This is a relatively small amount of land, and it is indicative of the fact that agriculture is a small-scale enterprise in Uttarakhand.
The other options are incorrect. Option (b) is 0.79 hectares. This is a slightly larger amount of land than the average, but it is still a relatively small amount. Option (c) is 0.99 hectares. This is a significantly larger amount of land than the average, and it is indicative of the fact that there are some farmers in Uttarakhand who own a relatively large amount of land. Option (d) is 0.89 hectares. This is a very close approximation to the average, but it is still incorrect.
In conclusion, the average size of land-holding in Uttarakhand is 0.69 hectares. This is a relatively small amount of land, and it is indicative of the fact that agriculture is a small-scale enterprise in Uttarakhand.