The correct answer is B. Cupshakes.
Cupshakes are radial splits which are wider on the outside of the log and narrower towards the pith. They are caused by a combination of factors, including the drying of the wood, the presence of knots, and the growth of the tree. Cupshakes can weaken the wood and make it more susceptible to decay.
Heart shakes are radial splits which start at the pith and extend to the outside of the log. They are caused by the drying of the wood, and they can weaken the wood.
Starshakes are radial splits which radiate from a central point in the log. They are caused by the drying of the wood, and they can weaken the wood.
Rindgalls are swellings on the bark of a tree. They are caused by a variety of factors, including insect damage, fungal infection, and mechanical injury. Rindgalls do not affect the strength of the wood.