I disagree it should be A
Answer:
The A band stays the same width and, at full contraction, the thin filaments overlap. ... The I band contains only thin filaments and also shortens. The A band does not shorten—it remains the same length—but A bands of different sarcomeres move closer together during contraction, eventually disappearing.
Even though amoeba, paramecium, and spirogyra are quite different, they are all often classified in the same group, Protista because this group holds various types of eukaryotic organisms that are heterotrophic and unicellular.
This type of classification is not based on evolutionary and genetic similarities, but only on the properties of being unicellular, so there are many vastly different organisms in this group.
E fdg dgr dgr d gd rgdrg dhh
Coronary vessels supply blood to heart muscles ..blockage in them will cause hypoxia in heart muscles which leads to heart attack