Option A is correct.
Cathy needs to collect linear data . She should collect the data of option A-The height of a building for 20 years.
Step-by-step explanation:
Linear data is that data whose slope is always same. Here lets assume, initially the building had 2 floors. Each year 2 floors are added above the previous floors. So our coordinate will be (0,2) (1,4) (2,6) (3,8) and so on.
So slope =
![(difference in y)/(difference in x)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/t0uy2e24dwrob5ntttkxvajkvypcs8sip6.png)
=
![(4-2)/(1-0) = (2)/(1)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/6dix9lpc7id6f93htycqjbkbyjn4jg4ywt.png)
=
=
![(2)/(1)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/raeppt2zqt7wuh1bz38lzn0ux8d11a7fkz.png)
So, here slope is 2 for all coordinates.