Do you *really* want the entire columns of D, E, F, and H to be included in
the Conditional Format?
If you do, then click on the column header of Column H, to select the entire
column, then hold down <Ctrl>, and click in the headers of F, E, and D, in
that order, so that you end up with cell D1 in focus (white).
Then,
<Format> <Conditional Format>
Change to "Formula Is", and enter this formula:
=D1=MIN($D:$F,$H:$H)
Click on "Format", and choose your Bold (or whatever), then <OK> <OK>.
Now, the lowest number in either of those 4 columns will display with the
format that you chose.
Needless to say, ties ( for lowest) will all display the chosen format.