A metamorphic rock is a type of rock which has been changed by extreme heat and pressure. so must be option D
The correct answer is: the treated glioblastoma cells were cultured in the presence of an inhibitor from umbilical cord stem cells, but the control cells were cultured without the inhibitor.
It has been shown that treatment with injected umbilical cord stem cells has strong therapeutic effects on glioma models. Those cells produce anti-tumour substances, with inhibitory effects.
Control group does not include the treatment in order to observe the treatment.
What are the options? I’ll help if u send the choices:)