A shaft of length $90 \: mm$ has a tapered portion of length $55 \: mm$. The diameter of the taper is $80 \: mm$ at one end and $65 \: mm$ at the other. If the taper is made by tailstock set over method, the taper angle and the set over respectively are

- $15^\circ 32′$ and $12.16 \: mm$
- $18^\circ 32′$ and $15.66 \: mm$
- $11^\circ 22′$ and $10.26 \: mm$
- $10^\circ 32′$ and $14.46 \: mm$