The correct option is A Fungus
𝘕𝘰𝘴𝘦𝘮𝘢 𝘣𝘰𝘮𝘣𝘺𝘤𝘪𝘴 is a fungus belonging to the order Microsporida. It attacks all life stages of Silk worm from egg to adult. Infected eggs are irregular in shape and do not hatch synchronously. Infected larvae suffer from loss of appetite and reduced growth rate and either they can't spin silk or spin it loosely. This disease is known as Pebrine disease which significantly affects the silk industry.
So, the correct answer is, 'Fungus'.