A node is a stem zone where the leaves are attached, the stem portion between nodes are called internodes, the thricomes are like little hairs in the leave and the lenticels are spaces in the leave that helps to transpiration like the stomata.
So, the stem regions at which leaves are attached are called nodes.
Also the name nodes is really common in gardening, it helps a lot to identify which leave are they talking about.
A systolic pressure of 112mmhg is a representation of the pressure in arteries during the contraction of the ventricles in the heart. So, C is correct. Systole means contraction while diastole means rest.
