A 40 yr female progressive dyspnoea from 1 yr. She also has b/I bibasilar end inspiratpory crepitation.True statement are :a) May be assocated with connective tissue diseaseb) Residual volume ↑edc) ↑ Total Lung Capacityd) HRCT is useful diagontic teste) FEV1 1/FVC ratio ↑ed