One of our PhD students is conducting research regarding the effect of greenhouse gas (different concentrations of CO₂) levels in the air on plant growth.She needs to grow the plants in a growth chamber so that the CO₂ concentration can be controlled. She has access to two growth chambers, and each chamber will hold five plants. According to this experimental design, this study system includes:

Select one:

a.

Plants as experimental units with growth chambers as pseudo-replicates

b.

Plants as experimental units with real replicates but blocked

c.

Plants as experimental units but pseudo-replicates

d.

Growth chamber as experimental units with plants as real replicates

e.

Growth chamber as experimental units with plants as pseudo-replicates