The correct option is 

a) 
The time taken in travelling DAB is less than that for BCD 
b) 
The time taken in travelling DAB is greater than that for BCD 
c) 
The time taken in travelling CDAD is less than that for ABC 
d) 
The time taken in travelling CDA is greater than that for ABC 
The correct option is 

a) 
The time taken in travelling DAB is less than that for BCD 
b) 
The time taken in travelling DAB is greater than that for BCD 
c) 
The time taken in travelling CDAD is less than that for ABC 
d) 
The time taken in travelling CDA is greater than that for ABC 
(b) From Kepler’s third law of planetary motion also known as law of periods Where is time period and the mean distance from the sun. Hence, greater is the distance of planet from sun, greater is its period of revolution. 