The smaller angle is $\frac 5{12}$ of a full circle.  A full circle has $360$ degrees, so the angle is $\frac 5{12}\times 360^{}\circ =150^{}\circ $.  So, the answer is $\rm D$. 
What is the angle between the hour hand and the minute hand at seven o\textquotesingle clock?~ ~ ．(Only consider angles less than 180^{}\circ) 
A. $50^{}\circ $ 
B. $120^{}\circ $ 
C. $135^{}\circ $ 
D. $150^{}\circ $ 
E. $165^{}\circ $ 