Dyslexia is one of several distinct learning disabilities. (i) It is a specific language-based disorder characterized by difficulties in single word decoding, usually reflecting insufficient phonological processing abilities. (ii) The difficulties in single word decoding are often unexpected in relation to age and other cognitive and academic abilities they are not the result of generalized developmental disability or sensory impairment. (iii) Manifested by variable difficulty with different forms of language, often including , in addition to problems reading a conspicuous problem with acquiring proficiency in writing and spelling. (iv) It is severe impairment in the ability to read, despite normal intelligence, normal opportunities to read, and an adequate home environment. a. i,ii,iii,iv b. iii,iv C. iv d. ii,iii,iv