Conduct a discrete Fourier transform on the y data. Note that when initially ready in$,\text{'}$y$\text{'}$ is a column in a data frame.

The fft function requires an input as an array, not a dataframe column $($or series$).$ To convert to an numpy array, use the line $\text{'}$ df$[\text{'}$y$\text{'}].$to$\_$numpy$()\text{'},$ assuming your data frame is named df$.$ What is the frequency of the lowest frequency spike in Hz$?$ a$.0\mathrm{.}50$ b$.1\mathrm{.}0$ c$.1\mathrm{.}5$ d$.3($edited$)$