so the answer is : B. Magnetic field reversal causes portions of the sun to die slowly over time, leaving dark marks.
<h2>Further explanation </h2>
Sunspots are the most prominent features of the sun; medium size spots about the size of the earth. Sunspots form and disappear for days or weeks. Sunspots are the coldest part of the sun and usually appear in pairs. Sunspots occur when a strong magnetic field appears on the sun's surface and causes the area to cool, from 6000 ° C to 4200 ° C; the area appears as a dark spot. The darkest area at the center of the spots is called the umbra; this is where the strongest magnetic field. The less dark areas around the umbra are called the penumbra. Sunspot activity is an 11-year cycle. Sunspots are an indicator of magnetic activity in the sun. Magnetic fields in spots store energy that is thrown in flares. As a result, flares usually appear in cycles that resemble 11-year cycles. Sunspots usually occur in groups (usually as simple pairs) but sometimes in complex arrangements with many complex spots and shapes. This unusual area often produces flares. Space weather forecasters use the complexity and shapes of sunspots to predict flares — the more complex the groups of spots there are, the more likely a flare will occur there.
For more than 300 years, the average number of sunspots regularly varies in an 11-year cycle. Every 11 years, the polarity of the magnetic field in the solar hemisphere changes. So, the complete solar magnetic cycle is 22 years.
<h3>Learn More :
</h3>
Sunspots; brainly.com/question/1652375,https://brainly.com/question/3095225,https://brainly.com/question/12701363.
<h3>Details
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Class: Junior high.
Subject: Biology.
Keywords: Sunspot, magnetic, earth.
