Read the following statements carefully.

(a) Photorespiration protects the plant from photo-oxidative damage by dissipating excess excitation energy.
(b) Above $40°\mathrm{C}$ the rate of respiration becomes high.
(c) Substrate level phosphorylation generates 8 ATP in glycolysis.
(d) Retting of stem fibres is carried out with the help of bacterial fermentation of softer tissues.

Pick up the correct statements.