The correct option is C Housekeeping gene
Housekeeping gene is expressed in all the cells in normal and pathological conditions. The genes which are expressed in all cell types and almost all the time. These genes are called housekeeping genes. These genes code for constitutive proteins and are constantly needed for cellular activities. Housekeeping genes are basically used to maintain the basic functions in a cell. So, the correct answer is 'Housekeeping gene'.