Kindly help in answering the following question

Explain the following terms and give an example of each: (a) Time selection (b) Spurious selection [5] A life office conducts quinquennial reviews of the mortality experience of male lives accepted at normal rates under its group life assurance business. The data are collected separately: (1) for "works" and "staff" employees; (2) according to duration since a life entered into assurance, into durations of less than one year and durations of one year and over. All lives are underwritten before being accepted for assurance.The following data relates to the last three investigations: Year Curtate Duration 0 Curtate Duration 1+ Eso Eso Works 1998 10,000 20 20,000 50 2003 8,421 16 20,000 48 2008 5,000 9 16.959 39 Staff 1998 10,000 16 5,000 10 2003 7,333 11 14,211 27 2008 2,143 33,889 61 (a) Identify all evidence of class selection and temporary initial selection in the above data. Give a justification in each case. (b) Aggregate the above data in three different ways and in each case determine whether spurious selection is present. (c) The same annual premium rate is charged for all members of the same age, and when the rates were last reviewed in 1999 it was decided to base them on the aggregate mortality rates at each age which emerged from the quinquennial investigation in 1998. The rates are now being reviewed, and it has been suggested that they should be based on the aggregate mortality rates at each age that emerged from the investigation in 2008. Comment on the mortality basis proposed for the new premium rates, in the case of the lives aged 50. [15] [Total 20]