Another term for top down estimating is:

A.
Anallogous estimating

B.
Life-cycle costing

C.
Parametric modelling

D.
Bottom up estimating

Explanation:
Analogous Estimating, is one form of expert judgment and it also known as Top-down Estimating. This technique is used to determine the duration of the project. After finalizing the high level scope/requirement, the PM will refer & compare the previously completed projects similar activities with the current activities and determine the duration.

This estimation technique will be applied to determine the duration when the detailed information about the project is not available, usually during the early stages of the project. This technique will look the scope/requirement as a whole single unit to estimate. This estimate will give a ball-park idea about the estimation and will have bigger variance.

Eg : To estimate the time required to complete the project of upgrading XYZ applications database version to a higher version, is to compare similar past projects and estimate the duration. This is done irrespective of the complexity, size and other factors.