Q: In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".
[header] How to solder electronics [title] Use a soldering iron with the appropriate heat control. [step] For soldering electrical components into printed circuit boards, the best soldering irons are electrostatic discharge (esd) safe, temperature-controlled, high-power irons. These will let you solder for hours, and are good for complex amateur radio projects. <sep> (A) [substeps] Make sure that the iron comes with a flame control (down in the manual that came with the machine). This can prevent sparks from spraying out of the iron when you solder it into circuit boards. (B) It also gets your circuit working at a dull temperature. [substeps] If you're on a lighter end of the spectrum, a soldering iron should work much better for you. (C) [substeps] These irons are not suitable for daily use by older people. If you would rather not use them, leave them to use for the day or so you will have time to solder. (D) For simple kits, an inexpensive pencil iron will do just fine. [substeps] Use a fixed power soldering iron , 25-watt for small jobs and 100-watt for larger jobs with heavy cabling.
A:
D