<prompt> Endemic disease is defined as -Disease occuring regularly in expected frequencyDisease occuring irregularlyDisease occuring in excess of expected freqencyDisease affecting a large population  <response>: Ans. is a i.e., Disease occuring regularly in expected frequency Sporadic - Disease occuring irregularly from time to time.Endemic - Disease occuring regularly in expected frequency.Epidemic - Disease occuring in excess of expected frequency.Pandemic - Epidemic affecting a large proportion of population over a wide geographic area. 